Browser "go back / go forward" visualization bug

[radrex]

1. Open Contest subdirectory
   e.g. Home/Contests/C# Development/ C# Advanced/C# OOP/C# OOP Exercises

2. "Go back" one page through browser
   only url and "Contest Archive" menu on the left change,
   BUT the page stays on the subdirectory "C# OOP Exercises" (doesn't visualize C# OOP directory in browser, and so on)

3. Once you reach "Home" page by clicking "go back", finally refreshes the page.
   Then if you "go forward" one page visualizes the subdirectory "C# OOP Exercises", but the url and "Contest Archive" menu on the left are at "C# Development"

Is that intentional for faster loading or is it a bug?